Reland of Injectable Obj-C video codecs

webrtc/sdk/objc/Framework/Classes/PeerConnection/RTCVideoCodec+Private.h

+/*
+ *  Copyright 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#import "WebRTC/RTCVideoCodec.h"
+
+#import "WebRTC/RTCVideoCodecH264.h"
+
+#include "webrtc/common_video/include/video_frame.h"
+#include "webrtc/media/base/codec.h"
+#include "webrtc/modules/video_coding/include/video_codec_interface.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+/* Interfaces for converting to/from internal C++ formats. */
+@interface RTCEncodedImage ()
+
+- (instancetype)initWithNativeEncodedImage:(webrtc::EncodedImage)encodedImage;
+- (webrtc::EncodedImage)toCpp;
+
+@end
+
+@interface RTCVideoEncoderSettings ()
+
+- (instancetype)initWithVideoCodec:(const webrtc::VideoCodec *__nullable)videoCodec;
+- (std::unique_ptr<webrtc::VideoCodec>)toCpp;
+
+@end
+
+@interface RTCCodecSpecificInfoH264 ()
+
+- (webrtc::CodecSpecificInfo)toCpp;
+
+@end
+
+@interface RTCRtpFragmentationHeader ()
+
+- (instancetype)initWithFragmentationHeader:
+        (const webrtc::RTPFragmentationHeader *__nullable)fragmentationHeader;
+- (std::unique_ptr<webrtc::RTPFragmentationHeader>)toCpp;
+
+@end
+
+@interface RTCVideoCodecInfo ()
+
+- (instancetype)initWithVideoCodec:(cricket::VideoCodec)videoCodec;
+- (cricket::VideoCodec)toCpp;
+
+@end
+
+NS_ASSUME_NONNULL_END